The basic principle behind most spectrometers involves the separation of different wavelength channels within an input beam onto different locations of an output plane using some type of dispersive element. The output may be detected using some type of detector array or a charged coupled device (CCD). Because of the scalar nature of the spectrum, such dispersive elements (e.g., gratings and prisms) generally provide a mapping between the different wavelengths and various spatial locations along a line on the detector. For example, for the case of a simple sinusoidal grating, dispersion is obtained across a line in a direction parallel to the grating vector. Thus, in the direction perpendicular to the grating vector, the light distribution at the output is similar to that at the input and does not carry any additional spectral information.